Unrecognized cervical spine injury can produce catastrophic neurologic disability. Sporadic reports of "occult" spine injury have generated concern, and physicians, fearing that they might fail to diagnose such an injury, have adopted the practice of radiographically imaging the spine in virtually all blunt trauma victims. This practice exposes large numbers of patients to x-ray imaging at considerable expense, while detecting injuries in small minority. Existing cervical spine injury data suggests that a limited number of clinical criteria can reliably identify patients who have "no risk" of cervical spine fracture or dislocation, and hence no need for x-rays, without misidentifying any injured patient. It is estimated that nation-wide implementation of these criteria will result in an annual reduction in radiographic charges of $60 million, and spare 125 individuals death from radiation induced thyroid malignancy. The long-term goal of this proposal is to reduce radiographic cervical spine imaging by demonstrating that clinical criteria can reliably exclude cervical spine injury in "no risk" blunt trauma victims without misidentifying any injured patient. This goal will be accomplished by confirming the following two hypothesis: I - Blunt trauma victims have no-risk of cervical spine fracture or dislocation if they meet all of the following criteria: 1) are awake and alert, 2) are not intoxicated, 3) have no tenderness on palpation of the bony cervical spine, and 4) have no other painful distracting injuries. II - Implementation of these criteria will reduce the number of radiographic spine evaluations without missing any significant cervical spine injuries. These hypotheses will be tested in a multicenter prospective study. The study protocol will require all blunt trauma victims presenting to participating emergency departments to undergo clinical evaluation prior to radiographic imaging. Presence or absence of the four clinical criteria, as well as presence or absence of cervical spine injury, will be documented for each patient. By demonstrating that cervical spine injury is absent in all identified "no risk" patients, the use of selective criteria will be validated. Validating the criteria with a high degree of statistical confidence will require 954 spine injury victims, necessitating evaluations on approximately 50,000 blunt trauma patients. Reductions in the number of radiographic evaluations will be determined by counting the number of radiographic evaluations performed on "no risk" patients. Charge reductions will be estimated by summing radiographic charges for all "no risk" patients. Reductions in radiation exposure will be determined by summing the life-time decrease in radiation morbidity and mortality for all "no risk" individuals.